xref: /linux-6.3-rc2/arch/arm/mach-omap2/powerdomain.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * OMAP powerdomain control
 *
 * Copyright (C) 2007-2008, 2011 Texas Instruments, Inc.
 * Copyright (C) 2007-2011 Nokia Corporation
 *
 * Written by Paul Walmsley
 * Added OMAP4 specific support by Abhijit Pagare <abhijitpagare@ti.com>
 * State counting code by Tero Kristo <tero.kristo@nokia.com>
 */
#undef DEBUG

#include <linux/cpu_pm.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <trace/events/power.h>

#include "cm2xxx_3xxx.h"
#include "prcm44xx.h"
#include "cm44xx.h"
#include "prm2xxx_3xxx.h"
#include "prm44xx.h"

#include <asm/cpu.h>

#include "powerdomain.h"
#include "clockdomain.h"
#include "voltage.h"

#include "soc.h"
#include "pm.h"

#define PWRDM_TRACE_STATES_FLAG	(1<<31)

static void pwrdms_save_context(void);
static void pwrdms_restore_context(void);

enum {
	PWRDM_STATE_NOW = 0,
	PWRDM_STATE_PREV,
};

/*
 * Types of sleep_switch used internally in omap_set_pwrdm_state()
 * and its associated static functions
 *
 * XXX Better documentation is needed here
 */
#define ALREADYACTIVE_SWITCH		0
#define FORCEWAKEUP_SWITCH		1
#define LOWPOWERSTATE_SWITCH		2

/* pwrdm_list contains all registered struct powerdomains */
static LIST_HEAD(pwrdm_list);

static struct pwrdm_ops *arch_pwrdm;

/* Private functions */

static struct powerdomain *_pwrdm_lookup(const char *name)
{
	struct powerdomain *pwrdm, *temp_pwrdm;

	pwrdm = NULL;

	list_for_each_entry(temp_pwrdm, &pwrdm_list, node) {
		if (!strcmp(name, temp_pwrdm->name)) {
			pwrdm = temp_pwrdm;
			break;
		}
	}

	return pwrdm;
}

/**
 * _pwrdm_register - register a powerdomain
 * @pwrdm: struct powerdomain * to register
 *
 * Adds a powerdomain to the internal powerdomain list.  Returns
 * -EINVAL if given a null pointer, -EEXIST if a powerdomain is
 * already registered by the provided name, or 0 upon success.
 */
static int _pwrdm_register(struct powerdomain *pwrdm)
{
	int i;
	struct voltagedomain *voltdm;

	if (!pwrdm || !pwrdm->name)
		return -EINVAL;

	if (cpu_is_omap44xx() &&
	    pwrdm->prcm_partition == OMAP4430_INVALID_PRCM_PARTITION) {
		pr_err("powerdomain: %s: missing OMAP4 PRCM partition ID\n",
		       pwrdm->name);
		return -EINVAL;
	}

	if (_pwrdm_lookup(pwrdm->name))
		return -EEXIST;

	if (arch_pwrdm && arch_pwrdm->pwrdm_has_voltdm)
		if (!arch_pwrdm->pwrdm_has_voltdm())
			goto skip_voltdm;

	voltdm = voltdm_lookup(pwrdm->voltdm.name);
	if (!voltdm) {
		pr_err("powerdomain: %s: voltagedomain %s does not exist\n",
		       pwrdm->name, pwrdm->voltdm.name);
		return -EINVAL;
	}
	pwrdm->voltdm.ptr = voltdm;
	INIT_LIST_HEAD(&pwrdm->voltdm_node);
skip_voltdm:
	spin_lock_init(&pwrdm->_lock);

	list_add(&pwrdm->node, &pwrdm_list);

	/* Initialize the powerdomain's state counter */
	for (i = 0; i < PWRDM_MAX_PWRSTS; i++)
		pwrdm->state_counter[i] = 0;

	pwrdm->ret_logic_off_counter = 0;
	for (i = 0; i < pwrdm->banks; i++)
		pwrdm->ret_mem_off_counter[i] = 0;

	if (arch_pwrdm && arch_pwrdm->pwrdm_wait_transition)
		arch_pwrdm->pwrdm_wait_transition(pwrdm);
	pwrdm->state = pwrdm_read_pwrst(pwrdm);
	pwrdm->state_counter[pwrdm->state] = 1;

	pr_debug("powerdomain: registered %s\n", pwrdm->name);

	return 0;
}

static void _update_logic_membank_counters(struct powerdomain *pwrdm)
{
	int i;
	u8 prev_logic_pwrst, prev_mem_pwrst;

	prev_logic_pwrst = pwrdm_read_prev_logic_pwrst(pwrdm);
	if ((pwrdm->pwrsts_logic_ret == PWRSTS_OFF_RET) &&
	    (prev_logic_pwrst == PWRDM_POWER_OFF))
		pwrdm->ret_logic_off_counter++;

	for (i = 0; i < pwrdm->banks; i++) {
		prev_mem_pwrst = pwrdm_read_prev_mem_pwrst(pwrdm, i);

		if ((pwrdm->pwrsts_mem_ret[i] == PWRSTS_OFF_RET) &&
		    (prev_mem_pwrst == PWRDM_POWER_OFF))
			pwrdm->ret_mem_off_counter[i]++;
	}
}

static int _pwrdm_state_switch(struct powerdomain *pwrdm, int flag)
{

	int prev, next, state, trace_state = 0;

	if (pwrdm == NULL)
		return -EINVAL;

	state = pwrdm_read_pwrst(pwrdm);

	switch (flag) {
	case PWRDM_STATE_NOW:
		prev = pwrdm->state;
		break;
	case PWRDM_STATE_PREV:
		prev = pwrdm_read_prev_pwrst(pwrdm);
		if (pwrdm->state != prev)
			pwrdm->state_counter[prev]++;
		if (prev == PWRDM_POWER_RET)
			_update_logic_membank_counters(pwrdm);
		/*
		 * If the power domain did not hit the desired state,
		 * generate a trace event with both the desired and hit states
		 */
		next = pwrdm_read_next_pwrst(pwrdm);
		if (next != prev) {
			trace_state = (PWRDM_TRACE_STATES_FLAG |
				       ((next & OMAP_POWERSTATE_MASK) << 8) |
				       ((prev & OMAP_POWERSTATE_MASK) << 0));
			trace_power_domain_target(pwrdm->name,
						  trace_state,
						  raw_smp_processor_id());
		}
		break;
	default:
		return -EINVAL;
	}

	if (state != prev)
		pwrdm->state_counter[state]++;

	pm_dbg_update_time(pwrdm, prev);

	pwrdm->state = state;

	return 0;
}

static int _pwrdm_pre_transition_cb(struct powerdomain *pwrdm, void *unused)
{
	pwrdm_clear_all_prev_pwrst(pwrdm);
	_pwrdm_state_switch(pwrdm, PWRDM_STATE_NOW);
	return 0;
}

static int _pwrdm_post_transition_cb(struct powerdomain *pwrdm, void *unused)
{
	_pwrdm_state_switch(pwrdm, PWRDM_STATE_PREV);
	return 0;
}

/**
 * _pwrdm_save_clkdm_state_and_activate - prepare for power state change
 * @pwrdm: struct powerdomain * to operate on
 * @curr_pwrst: current power state of @pwrdm
 * @pwrst: power state to switch to
 *
 * Determine whether the powerdomain needs to be turned on before
 * attempting to switch power states.  Called by
 * omap_set_pwrdm_state().  NOTE that if the powerdomain contains
 * multiple clockdomains, this code assumes that the first clockdomain
 * supports software-supervised wakeup mode - potentially a problem.
 * Returns the power state switch mode currently in use (see the
 * "Types of sleep_switch" comment above).
 */
static u8 _pwrdm_save_clkdm_state_and_activate(struct powerdomain *pwrdm,
					       u8 curr_pwrst, u8 pwrst)
{
	u8 sleep_switch;

	if (curr_pwrst < PWRDM_POWER_ON) {
		if (curr_pwrst > pwrst &&
		    pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE &&
		    arch_pwrdm->pwrdm_set_lowpwrstchange) {
			sleep_switch = LOWPOWERSTATE_SWITCH;
		} else {
			clkdm_deny_idle_nolock(pwrdm->pwrdm_clkdms[0]);
			sleep_switch = FORCEWAKEUP_SWITCH;
		}
	} else {
		sleep_switch = ALREADYACTIVE_SWITCH;
	}

	return sleep_switch;
}

/**
 * _pwrdm_restore_clkdm_state - restore the clkdm hwsup state after pwrst change
 * @pwrdm: struct powerdomain * to operate on
 * @sleep_switch: return value from _pwrdm_save_clkdm_state_and_activate()
 *
 * Restore the clockdomain state perturbed by
 * _pwrdm_save_clkdm_state_and_activate(), and call the power state
 * bookkeeping code.  Called by omap_set_pwrdm_state().  NOTE that if
 * the powerdomain contains multiple clockdomains, this assumes that
 * the first associated clockdomain supports either
 * hardware-supervised idle control in the register, or
 * software-supervised sleep.  No return value.
 */
static void _pwrdm_restore_clkdm_state(struct powerdomain *pwrdm,
				       u8 sleep_switch)
{
	switch (sleep_switch) {
	case FORCEWAKEUP_SWITCH:
		clkdm_allow_idle_nolock(pwrdm->pwrdm_clkdms[0]);
		break;
	case LOWPOWERSTATE_SWITCH:
		if (pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE &&
		    arch_pwrdm->pwrdm_set_lowpwrstchange)
			arch_pwrdm->pwrdm_set_lowpwrstchange(pwrdm);
		pwrdm_state_switch_nolock(pwrdm);
		break;
	}
}

/* Public functions */

/**
 * pwrdm_register_platform_funcs - register powerdomain implementation fns
 * @po: func pointers for arch specific implementations
 *
 * Register the list of function pointers used to implement the
 * powerdomain functions on different OMAP SoCs.  Should be called
 * before any other pwrdm_register*() function.  Returns -EINVAL if
 * @po is null, -EEXIST if platform functions have already been
 * registered, or 0 upon success.
 */
int pwrdm_register_platform_funcs(struct pwrdm_ops *po)
{
	if (!po)
		return -EINVAL;

	if (arch_pwrdm)
		return -EEXIST;

	arch_pwrdm = po;

	return 0;
}

/**
 * pwrdm_register_pwrdms - register SoC powerdomains
 * @ps: pointer to an array of struct powerdomain to register
 *
 * Register the powerdomains available on a particular OMAP SoC.  Must
 * be called after pwrdm_register_platform_funcs().  May be called
 * multiple times.  Returns -EACCES if called before
 * pwrdm_register_platform_funcs(); -EINVAL if the argument @ps is
 * null; or 0 upon success.
 */
int pwrdm_register_pwrdms(struct powerdomain **ps)
{
	struct powerdomain **p = NULL;

	if (!arch_pwrdm)
		return -EEXIST;

	if (!ps)
		return -EINVAL;

	for (p = ps; *p; p++)
		_pwrdm_register(*p);

	return 0;
}

static int cpu_notifier(struct notifier_block *nb, unsigned long cmd, void *v)
{
	switch (cmd) {
	case CPU_CLUSTER_PM_ENTER:
		if (enable_off_mode)
			pwrdms_save_context();
		break;
	case CPU_CLUSTER_PM_EXIT:
		if (enable_off_mode)
			pwrdms_restore_context();
		break;
	}

	return NOTIFY_OK;
}

/**
 * pwrdm_complete_init - set up the powerdomain layer
 *
 * Do whatever is necessary to initialize registered powerdomains and
 * powerdomain code.  Currently, this programs the next power state
 * for each powerdomain to ON.  This prevents powerdomains from
 * unexpectedly losing context or entering high wakeup latency modes
 * with non-power-management-enabled kernels.  Must be called after
 * pwrdm_register_pwrdms().  Returns -EACCES if called before
 * pwrdm_register_pwrdms(), or 0 upon success.
 */
int pwrdm_complete_init(void)
{
	struct powerdomain *temp_p;
	static struct notifier_block nb;

	if (list_empty(&pwrdm_list))
		return -EACCES;

	list_for_each_entry(temp_p, &pwrdm_list, node)
		pwrdm_set_next_pwrst(temp_p, PWRDM_POWER_ON);

	/* Only AM43XX can lose pwrdm context during rtc-ddr suspend */
	if (soc_is_am43xx()) {
		nb.notifier_call = cpu_notifier;
		cpu_pm_register_notifier(&nb);
	}

	return 0;
}

/**
 * pwrdm_lock - acquire a Linux spinlock on a powerdomain
 * @pwrdm: struct powerdomain * to lock
 *
 * Acquire the powerdomain spinlock on @pwrdm.  No return value.
 */
void pwrdm_lock(struct powerdomain *pwrdm)
	__acquires(&pwrdm->_lock)
{
	spin_lock_irqsave(&pwrdm->_lock, pwrdm->_lock_flags);
}

/**
 * pwrdm_unlock - release a Linux spinlock on a powerdomain
 * @pwrdm: struct powerdomain * to unlock
 *
 * Release the powerdomain spinlock on @pwrdm.  No return value.
 */
void pwrdm_unlock(struct powerdomain *pwrdm)
	__releases(&pwrdm->_lock)
{
	spin_unlock_irqrestore(&pwrdm->_lock, pwrdm->_lock_flags);
}

/**
 * pwrdm_lookup - look up a powerdomain by name, return a pointer
 * @name: name of powerdomain
 *
 * Find a registered powerdomain by its name @name.  Returns a pointer
 * to the struct powerdomain if found, or NULL otherwise.
 */
struct powerdomain *pwrdm_lookup(const char *name)
{
	struct powerdomain *pwrdm;

	if (!name)
		return NULL;

	pwrdm = _pwrdm_lookup(name);

	return pwrdm;
}

/**
 * pwrdm_for_each - call function on each registered clockdomain
 * @fn: callback function *
 *
 * Call the supplied function @fn for each registered powerdomain.
 * The callback function @fn can return anything but 0 to bail out
 * early from the iterator.  Returns the last return value of the
 * callback function, which should be 0 for success or anything else
 * to indicate failure; or -EINVAL if the function pointer is null.
 */
int pwrdm_for_each(int (*fn)(struct powerdomain *pwrdm, void *user),
		   void *user)
{
	struct powerdomain *temp_pwrdm;
	int ret = 0;

	if (!fn)
		return -EINVAL;

	list_for_each_entry(temp_pwrdm, &pwrdm_list, node) {
		ret = (*fn)(temp_pwrdm, user);
		if (ret)
			break;
	}

	return ret;
}

/**
 * pwrdm_add_clkdm - add a clockdomain to a powerdomain
 * @pwrdm: struct powerdomain * to add the clockdomain to
 * @clkdm: struct clockdomain * to associate with a powerdomain
 *
 * Associate the clockdomain @clkdm with a powerdomain @pwrdm.  This
 * enables the use of pwrdm_for_each_clkdm().  Returns -EINVAL if
 * presented with invalid pointers; -ENOMEM if memory could not be allocated;
 * or 0 upon success.
 */
int pwrdm_add_clkdm(struct powerdomain *pwrdm, struct clockdomain *clkdm)
{
	int i;
	int ret = -EINVAL;

	if (!pwrdm || !clkdm)
		return -EINVAL;

	pr_debug("powerdomain: %s: associating clockdomain %s\n",
		 pwrdm->name, clkdm->name);

	for (i = 0; i < PWRDM_MAX_CLKDMS; i++) {
		if (!pwrdm->pwrdm_clkdms[i])
			break;
#ifdef DEBUG
		if (pwrdm->pwrdm_clkdms[i] == clkdm) {
			ret = -EINVAL;
			goto pac_exit;
		}
#endif
	}

	if (i == PWRDM_MAX_CLKDMS) {
		pr_debug("powerdomain: %s: increase PWRDM_MAX_CLKDMS for clkdm %s\n",
			 pwrdm->name, clkdm->name);
		WARN_ON(1);
		ret = -ENOMEM;
		goto pac_exit;
	}

	pwrdm->pwrdm_clkdms[i] = clkdm;

	ret = 0;

pac_exit:
	return ret;
}

/**
 * pwrdm_get_mem_bank_count - get number of memory banks in this powerdomain
 * @pwrdm: struct powerdomain *
 *
 * Return the number of controllable memory banks in powerdomain @pwrdm,
 * starting with 1.  Returns -EINVAL if the powerdomain pointer is null.
 */
int pwrdm_get_mem_bank_count(struct powerdomain *pwrdm)
{
	if (!pwrdm)
		return -EINVAL;

	return pwrdm->banks;
}

/**
 * pwrdm_set_next_pwrst - set next powerdomain power state
 * @pwrdm: struct powerdomain * to set
 * @pwrst: one of the PWRDM_POWER_* macros
 *
 * Set the powerdomain @pwrdm's next power state to @pwrst.  The powerdomain
 * may not enter this state immediately if the preconditions for this state
 * have not been satisfied.  Returns -EINVAL if the powerdomain pointer is
 * null or if the power state is invalid for the powerdomin, or returns 0
 * upon success.
 */
int pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return -EINVAL;

	if (!(pwrdm->pwrsts & (1 << pwrst)))
		return -EINVAL;

	pr_debug("powerdomain: %s: setting next powerstate to %0x\n",
		 pwrdm->name, pwrst);

	if (arch_pwrdm && arch_pwrdm->pwrdm_set_next_pwrst) {
		/* Trace the pwrdm desired target state */
		trace_power_domain_target(pwrdm->name, pwrst,
					  raw_smp_processor_id());
		/* Program the pwrdm desired target state */
		ret = arch_pwrdm->pwrdm_set_next_pwrst(pwrdm, pwrst);
	}

	return ret;
}

/**
 * pwrdm_read_next_pwrst - get next powerdomain power state
 * @pwrdm: struct powerdomain * to get power state
 *
 * Return the powerdomain @pwrdm's next power state.  Returns -EINVAL
 * if the powerdomain pointer is null or returns the next power state
 * upon success.
 */
int pwrdm_read_next_pwrst(struct powerdomain *pwrdm)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return -EINVAL;

	if (arch_pwrdm && arch_pwrdm->pwrdm_read_next_pwrst)
		ret = arch_pwrdm->pwrdm_read_next_pwrst(pwrdm);

	return ret;
}

/**
 * pwrdm_read_pwrst - get current powerdomain power state
 * @pwrdm: struct powerdomain * to get power state
 *
 * Return the powerdomain @pwrdm's current power state.	Returns -EINVAL
 * if the powerdomain pointer is null or returns the current power state
 * upon success. Note that if the power domain only supports the ON state
 * then just return ON as the current state.
 */
int pwrdm_read_pwrst(struct powerdomain *pwrdm)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return -EINVAL;

	if (pwrdm->pwrsts == PWRSTS_ON)
		return PWRDM_POWER_ON;

	if (arch_pwrdm && arch_pwrdm->pwrdm_read_pwrst)
		ret = arch_pwrdm->pwrdm_read_pwrst(pwrdm);

	return ret;
}

/**
 * pwrdm_read_prev_pwrst - get previous powerdomain power state
 * @pwrdm: struct powerdomain * to get previous power state
 *
 * Return the powerdomain @pwrdm's previous power state.  Returns -EINVAL
 * if the powerdomain pointer is null or returns the previous power state
 * upon success.
 */
int pwrdm_read_prev_pwrst(struct powerdomain *pwrdm)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return -EINVAL;

	if (arch_pwrdm && arch_pwrdm->pwrdm_read_prev_pwrst)
		ret = arch_pwrdm->pwrdm_read_prev_pwrst(pwrdm);

	return ret;
}

/**
 * pwrdm_set_logic_retst - set powerdomain logic power state upon retention
 * @pwrdm: struct powerdomain * to set
 * @pwrst: one of the PWRDM_POWER_* macros
 *
 * Set the next power state @pwrst that the logic portion of the
 * powerdomain @pwrdm will enter when the powerdomain enters retention.
 * This will be either RETENTION or OFF, if supported.  Returns
 * -EINVAL if the powerdomain pointer is null or the target power
 * state is not supported, or returns 0 upon success.
 */
int pwrdm_set_logic_retst(struct powerdomain *pwrdm, u8 pwrst)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return -EINVAL;

	if (!(pwrdm->pwrsts_logic_ret & (1 << pwrst)))
		return -EINVAL;

	pr_debug("powerdomain: %s: setting next logic powerstate to %0x\n",
		 pwrdm->name, pwrst);

	if (arch_pwrdm && arch_pwrdm->pwrdm_set_logic_retst)
		ret = arch_pwrdm->pwrdm_set_logic_retst(pwrdm, pwrst);

	return ret;
}

/**
 * pwrdm_set_mem_onst - set memory power state while powerdomain ON
 * @pwrdm: struct powerdomain * to set
 * @bank: memory bank number to set (0-3)
 * @pwrst: one of the PWRDM_POWER_* macros
 *
 * Set the next power state @pwrst that memory bank @bank of the
 * powerdomain @pwrdm will enter when the powerdomain enters the ON
 * state.  @bank will be a number from 0 to 3, and represents different
 * types of memory, depending on the powerdomain.  Returns -EINVAL if
 * the powerdomain pointer is null or the target power state is not
 * supported for this memory bank, -EEXIST if the target memory
 * bank does not exist or is not controllable, or returns 0 upon
 * success.
 */
int pwrdm_set_mem_onst(struct powerdomain *pwrdm, u8 bank, u8 pwrst)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return -EINVAL;

	if (pwrdm->banks < (bank + 1))
		return -EEXIST;

	if (!(pwrdm->pwrsts_mem_on[bank] & (1 << pwrst)))
		return -EINVAL;

	pr_debug("powerdomain: %s: setting next memory powerstate for bank %0x while pwrdm-ON to %0x\n",
		 pwrdm->name, bank, pwrst);

	if (arch_pwrdm && arch_pwrdm->pwrdm_set_mem_onst)
		ret = arch_pwrdm->pwrdm_set_mem_onst(pwrdm, bank, pwrst);

	return ret;
}

/**
 * pwrdm_set_mem_retst - set memory power state while powerdomain in RET
 * @pwrdm: struct powerdomain * to set
 * @bank: memory bank number to set (0-3)
 * @pwrst: one of the PWRDM_POWER_* macros
 *
 * Set the next power state @pwrst that memory bank @bank of the
 * powerdomain @pwrdm will enter when the powerdomain enters the
 * RETENTION state.  Bank will be a number from 0 to 3, and represents
 * different types of memory, depending on the powerdomain.  @pwrst
 * will be either RETENTION or OFF, if supported.  Returns -EINVAL if
 * the powerdomain pointer is null or the target power state is not
 * supported for this memory bank, -EEXIST if the target memory
 * bank does not exist or is not controllable, or returns 0 upon
 * success.
 */
int pwrdm_set_mem_retst(struct powerdomain *pwrdm, u8 bank, u8 pwrst)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return -EINVAL;

	if (pwrdm->banks < (bank + 1))
		return -EEXIST;

	if (!(pwrdm->pwrsts_mem_ret[bank] & (1 << pwrst)))
		return -EINVAL;

	pr_debug("powerdomain: %s: setting next memory powerstate for bank %0x while pwrdm-RET to %0x\n",
		 pwrdm->name, bank, pwrst);

	if (arch_pwrdm && arch_pwrdm->pwrdm_set_mem_retst)
		ret = arch_pwrdm->pwrdm_set_mem_retst(pwrdm, bank, pwrst);

	return ret;
}

/**
 * pwrdm_read_logic_pwrst - get current powerdomain logic retention power state
 * @pwrdm: struct powerdomain * to get current logic retention power state
 *
 * Return the power state that the logic portion of powerdomain @pwrdm
 * will enter when the powerdomain enters retention.  Returns -EINVAL
 * if the powerdomain pointer is null or returns the logic retention
 * power state upon success.
 */
int pwrdm_read_logic_pwrst(struct powerdomain *pwrdm)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return -EINVAL;

	if (arch_pwrdm && arch_pwrdm->pwrdm_read_logic_pwrst)
		ret = arch_pwrdm->pwrdm_read_logic_pwrst(pwrdm);

	return ret;
}

/**
 * pwrdm_read_prev_logic_pwrst - get previous powerdomain logic power state
 * @pwrdm: struct powerdomain * to get previous logic power state
 *
 * Return the powerdomain @pwrdm's previous logic power state.  Returns
 * -EINVAL if the powerdomain pointer is null or returns the previous
 * logic power state upon success.
 */
int pwrdm_read_prev_logic_pwrst(struct powerdomain *pwrdm)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return -EINVAL;

	if (arch_pwrdm && arch_pwrdm->pwrdm_read_prev_logic_pwrst)
		ret = arch_pwrdm->pwrdm_read_prev_logic_pwrst(pwrdm);

	return ret;
}

/**
 * pwrdm_read_logic_retst - get next powerdomain logic power state
 * @pwrdm: struct powerdomain * to get next logic power state
 *
 * Return the powerdomain pwrdm's logic power state.  Returns -EINVAL
 * if the powerdomain pointer is null or returns the next logic
 * power state upon success.
 */
int pwrdm_read_logic_retst(struct powerdomain *pwrdm)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return -EINVAL;

	if (arch_pwrdm && arch_pwrdm->pwrdm_read_logic_retst)
		ret = arch_pwrdm->pwrdm_read_logic_retst(pwrdm);

	return ret;
}

/**
 * pwrdm_read_mem_pwrst - get current memory bank power state
 * @pwrdm: struct powerdomain * to get current memory bank power state
 * @bank: memory bank number (0-3)
 *
 * Return the powerdomain @pwrdm's current memory power state for bank
 * @bank.  Returns -EINVAL if the powerdomain pointer is null, -EEXIST if
 * the target memory bank does not exist or is not controllable, or
 * returns the current memory power state upon success.
 */
int pwrdm_read_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return ret;

	if (pwrdm->banks < (bank + 1))
		return ret;

	if (pwrdm->flags & PWRDM_HAS_MPU_QUIRK)
		bank = 1;

	if (arch_pwrdm && arch_pwrdm->pwrdm_read_mem_pwrst)
		ret = arch_pwrdm->pwrdm_read_mem_pwrst(pwrdm, bank);

	return ret;
}

/**
 * pwrdm_read_prev_mem_pwrst - get previous memory bank power state
 * @pwrdm: struct powerdomain * to get previous memory bank power state
 * @bank: memory bank number (0-3)
 *
 * Return the powerdomain @pwrdm's previous memory power state for
 * bank @bank.  Returns -EINVAL if the powerdomain pointer is null,
 * -EEXIST if the target memory bank does not exist or is not
 * controllable, or returns the previous memory power state upon
 * success.
 */
int pwrdm_read_prev_mem_pwrst(struct powerdomain *pwrdm, u8 bank)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return ret;

	if (pwrdm->banks < (bank + 1))
		return ret;

	if (pwrdm->flags & PWRDM_HAS_MPU_QUIRK)
		bank = 1;

	if (arch_pwrdm && arch_pwrdm->pwrdm_read_prev_mem_pwrst)
		ret = arch_pwrdm->pwrdm_read_prev_mem_pwrst(pwrdm, bank);

	return ret;
}

/**
 * pwrdm_read_mem_retst - get next memory bank power state
 * @pwrdm: struct powerdomain * to get mext memory bank power state
 * @bank: memory bank number (0-3)
 *
 * Return the powerdomain pwrdm's next memory power state for bank
 * x.  Returns -EINVAL if the powerdomain pointer is null, -EEXIST if
 * the target memory bank does not exist or is not controllable, or
 * returns the next memory power state upon success.
 */
int pwrdm_read_mem_retst(struct powerdomain *pwrdm, u8 bank)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return ret;

	if (pwrdm->banks < (bank + 1))
		return ret;

	if (arch_pwrdm && arch_pwrdm->pwrdm_read_mem_retst)
		ret = arch_pwrdm->pwrdm_read_mem_retst(pwrdm, bank);

	return ret;
}

/**
 * pwrdm_clear_all_prev_pwrst - clear previous powerstate register for a pwrdm
 * @pwrdm: struct powerdomain * to clear
 *
 * Clear the powerdomain's previous power state register @pwrdm.
 * Clears the entire register, including logic and memory bank
 * previous power states.  Returns -EINVAL if the powerdomain pointer
 * is null, or returns 0 upon success.
 */
int pwrdm_clear_all_prev_pwrst(struct powerdomain *pwrdm)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return ret;

	/*
	 * XXX should get the powerdomain's current state here;
	 * warn & fail if it is not ON.
	 */

	pr_debug("powerdomain: %s: clearing previous power state reg\n",
		 pwrdm->name);

	if (arch_pwrdm && arch_pwrdm->pwrdm_clear_all_prev_pwrst)
		ret = arch_pwrdm->pwrdm_clear_all_prev_pwrst(pwrdm);

	return ret;
}

/**
 * pwrdm_enable_hdwr_sar - enable automatic hardware SAR for a pwrdm
 * @pwrdm: struct powerdomain *
 *
 * Enable automatic context save-and-restore upon power state change
 * for some devices in the powerdomain @pwrdm.  Warning: this only
 * affects a subset of devices in a powerdomain; check the TRM
 * closely.  Returns -EINVAL if the powerdomain pointer is null or if
 * the powerdomain does not support automatic save-and-restore, or
 * returns 0 upon success.
 */
int pwrdm_enable_hdwr_sar(struct powerdomain *pwrdm)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return ret;

	if (!(pwrdm->flags & PWRDM_HAS_HDWR_SAR))
		return ret;

	pr_debug("powerdomain: %s: setting SAVEANDRESTORE bit\n", pwrdm->name);

	if (arch_pwrdm && arch_pwrdm->pwrdm_enable_hdwr_sar)
		ret = arch_pwrdm->pwrdm_enable_hdwr_sar(pwrdm);

	return ret;
}

/**
 * pwrdm_disable_hdwr_sar - disable automatic hardware SAR for a pwrdm
 * @pwrdm: struct powerdomain *
 *
 * Disable automatic context save-and-restore upon power state change
 * for some devices in the powerdomain @pwrdm.  Warning: this only
 * affects a subset of devices in a powerdomain; check the TRM
 * closely.  Returns -EINVAL if the powerdomain pointer is null or if
 * the powerdomain does not support automatic save-and-restore, or
 * returns 0 upon success.
 */
int pwrdm_disable_hdwr_sar(struct powerdomain *pwrdm)
{
	int ret = -EINVAL;

	if (!pwrdm)
		return ret;

	if (!(pwrdm->flags & PWRDM_HAS_HDWR_SAR))
		return ret;

	pr_debug("powerdomain: %s: clearing SAVEANDRESTORE bit\n", pwrdm->name);

	if (arch_pwrdm && arch_pwrdm->pwrdm_disable_hdwr_sar)
		ret = arch_pwrdm->pwrdm_disable_hdwr_sar(pwrdm);

	return ret;
}

/**
 * pwrdm_has_hdwr_sar - test whether powerdomain supports hardware SAR
 * @pwrdm: struct powerdomain *
 *
 * Returns 1 if powerdomain @pwrdm supports hardware save-and-restore
 * for some devices, or 0 if it does not.
 */
bool pwrdm_has_hdwr_sar(struct powerdomain *pwrdm)
{
	return (pwrdm && pwrdm->flags & PWRDM_HAS_HDWR_SAR) ? 1 : 0;
}

int pwrdm_state_switch_nolock(struct powerdomain *pwrdm)
{
	int ret;

	if (!pwrdm || !arch_pwrdm)
		return -EINVAL;

	ret = arch_pwrdm->pwrdm_wait_transition(pwrdm);
	if (!ret)
		ret = _pwrdm_state_switch(pwrdm, PWRDM_STATE_NOW);

	return ret;
}

int __deprecated pwrdm_state_switch(struct powerdomain *pwrdm)
{
	int ret;

	pwrdm_lock(pwrdm);
	ret = pwrdm_state_switch_nolock(pwrdm);
	pwrdm_unlock(pwrdm);

	return ret;
}

int pwrdm_pre_transition(struct powerdomain *pwrdm)
{
	if (pwrdm)
		_pwrdm_pre_transition_cb(pwrdm, NULL);
	else
		pwrdm_for_each(_pwrdm_pre_transition_cb, NULL);

	return 0;
}

int pwrdm_post_transition(struct powerdomain *pwrdm)
{
	if (pwrdm)
		_pwrdm_post_transition_cb(pwrdm, NULL);
	else
		pwrdm_for_each(_pwrdm_post_transition_cb, NULL);

	return 0;
}

/**
 * pwrdm_get_valid_lp_state() - Find best match deep power state
 * @pwrdm:	power domain for which we want to find best match
 * @is_logic_state: Are we looking for logic state match here? Should
 *		    be one of PWRDM_xxx macro values
 * @req_state:	requested power state
 *
 * Returns: closest match for requested power state. default fallback
 * is RET for logic state and ON for power state.
 *
 * This does a search from the power domain data looking for the
 * closest valid power domain state that the hardware can achieve.
 * PRCM definitions for PWRSTCTRL allows us to program whatever
 * configuration we'd like, and PRCM will actually attempt such
 * a transition, however if the powerdomain does not actually support it,
 * we endup with a hung system. The valid power domain states are already
 * available in our powerdomain data files. So this function tries to do
 * the following:
 * a) find if we have an exact match to the request - no issues.
 * b) else find if a deeper power state is possible.
 * c) failing which, it tries to find closest higher power state for the
 * request.
 */
u8 pwrdm_get_valid_lp_state(struct powerdomain *pwrdm,
			    bool is_logic_state, u8 req_state)
{
	u8 pwrdm_states = is_logic_state ? pwrdm->pwrsts_logic_ret :
			pwrdm->pwrsts;
	/* For logic, ret is highest and others, ON is highest */
	u8 default_pwrst = is_logic_state ? PWRDM_POWER_RET : PWRDM_POWER_ON;
	u8 new_pwrst;
	bool found;

	/* If it is already supported, nothing to search */
	if (pwrdm_states & BIT(req_state))
		return req_state;

	if (!req_state)
		goto up_search;

	/*
	 * So, we dont have a exact match
	 * Can we get a deeper power state match?
	 */
	new_pwrst = req_state - 1;
	found = true;
	while (!(pwrdm_states & BIT(new_pwrst))) {
		/* No match even at OFF? Not available */
		if (new_pwrst == PWRDM_POWER_OFF) {
			found = false;
			break;
		}
		new_pwrst--;
	}

	if (found)
		goto done;

up_search:
	/* OK, no deeper ones, can we get a higher match? */
	new_pwrst = req_state + 1;
	while (!(pwrdm_states & BIT(new_pwrst))) {
		if (new_pwrst > PWRDM_POWER_ON) {
			WARN(1, "powerdomain: %s: Fix max powerstate to ON\n",
			     pwrdm->name);
			return PWRDM_POWER_ON;
		}

		if (new_pwrst == default_pwrst)
			break;
		new_pwrst++;
	}
done:
	return new_pwrst;
}

/**
 * omap_set_pwrdm_state - change a powerdomain's current power state
 * @pwrdm: struct powerdomain * to change the power state of
 * @pwrst: power state to change to
 *
 * Change the current hardware power state of the powerdomain
 * represented by @pwrdm to the power state represented by @pwrst.
 * Returns -EINVAL if @pwrdm is null or invalid or if the
 * powerdomain's current power state could not be read, or returns 0
 * upon success or if @pwrdm does not support @pwrst or any
 * lower-power state.  XXX Should not return 0 if the @pwrdm does not
 * support @pwrst or any lower-power state: this should be an error.
 */
int omap_set_pwrdm_state(struct powerdomain *pwrdm, u8 pwrst)
{
	u8 next_pwrst, sleep_switch;
	int curr_pwrst;
	int ret = 0;

	if (!pwrdm || IS_ERR(pwrdm))
		return -EINVAL;

	while (!(pwrdm->pwrsts & (1 << pwrst))) {
		if (pwrst == PWRDM_POWER_OFF)
			return ret;
		pwrst--;
	}

	pwrdm_lock(pwrdm);

	curr_pwrst = pwrdm_read_pwrst(pwrdm);
	if (curr_pwrst < 0) {
		ret = -EINVAL;
		goto osps_out;
	}

	next_pwrst = pwrdm_read_next_pwrst(pwrdm);
	if (curr_pwrst == pwrst && next_pwrst == pwrst)
		goto osps_out;

	sleep_switch = _pwrdm_save_clkdm_state_and_activate(pwrdm, curr_pwrst,
							    pwrst);

	ret = pwrdm_set_next_pwrst(pwrdm, pwrst);
	if (ret)
		pr_err("%s: unable to set power state of powerdomain: %s\n",
		       __func__, pwrdm->name);

	_pwrdm_restore_clkdm_state(pwrdm, sleep_switch);

osps_out:
	pwrdm_unlock(pwrdm);

	return ret;
}

/**
 * pwrdm_save_context - save powerdomain registers
 *
 * Register state is going to be lost due to a suspend or hibernate
 * event. Save the powerdomain registers.
 */
static int pwrdm_save_context(struct powerdomain *pwrdm, void *unused)
{
	if (arch_pwrdm && arch_pwrdm->pwrdm_save_context)
		arch_pwrdm->pwrdm_save_context(pwrdm);
	return 0;
}

/**
 * pwrdm_save_context - restore powerdomain registers
 *
 * Restore powerdomain control registers after a suspend or resume
 * event.
 */
static int pwrdm_restore_context(struct powerdomain *pwrdm, void *unused)
{
	if (arch_pwrdm && arch_pwrdm->pwrdm_restore_context)
		arch_pwrdm->pwrdm_restore_context(pwrdm);
	return 0;
}

static void pwrdms_save_context(void)
{
	pwrdm_for_each(pwrdm_save_context, NULL);
}

static void pwrdms_restore_context(void)
{
	pwrdm_for_each(pwrdm_restore_context, NULL);
}